Assessment of Forest Degradation in Omo-Sashsa- Oluwa Forest Reserves, Southwestern Nigeria

Forest degradation is a major environmental problem in many developing countries within the tropics. The Omo- Shasha- Oluwa forests is one of the most densely populated areas in Africa, and already shows high levels of human activity. The study intends to investigate changes in forest integrity due to anthropogenic activities by assessing flora biodiversity in study area and determining the trend of degradation using time series mapping. Stratified random sampling technique will be used to select sampling plots. 0.5km by 0.5 km grid will be overlaid on the land use land cover map and 5 representative plots each for the vegetated land use classes will be selected. Garmin 78 hand held GPS with an accuracy of 3 meters will be used to locate the center of the selected plots. The concentric plot assessment system will be used to select sub plots. Each modified plot is a cluster of four circular 17.95 m radius annular plots with one central 0.1 ha annular plot, three satellite 0.1 ha annular plots, four 7.32m subplots, and one 2.77 m radius micro plot. Each modified plot also contains three 17.95m long transects from the cluster center, with the first transect positioned at a random azimuth and the others at 60° and 120° from the first transect. Complete vegetation assessment will be carried within the sampled plots during field survey. Maximum likelihood algorithm will be used for the supervised classification after which validation and accuracy assessment will be conducted. Land change detection will be carried out using suitable GIS software. The data collected in situ from the field will be subjected to appropriate statistical analysis to determine the impact of degradation on the tropical forest. The result will provide invaluable information on the current landuse dynamics in the forest reserves of Southwestern Nigeria.